This book examines John Chrysostom's condemnation of the theatre and other popular spectacles as well as his attempts to harness their power through various forms of Christian spiritual theatre. Christoph Jacob addresses Chrysostom's rejection of public entertainment through an examination of the preacher's understanding of psychology and morality. He emphasises that Chrysostom's writings cannot be used as straightforward evidence for the nature of public secular entertainment in late antiquity. Instead of attempting to describe the performances, Jacob asks precisely which features of the theatre appeared to pose a threat to Christians. In addition to theatre attendance competing with churchgoing, the spectacles distracted people's attention from spiritual matters in general. The theatre was also closely associated with illicit sexual behaviour, something noted by pagan and Christian moralists alike. The key problem for Chrysostom, however, was the moral transformation that took place at spectacles: a theatregoer, just by watching an immoral play or hearing an immoral song, became immoral. Chrysostom worried not merely about how the bad examples of the performers might inspire illicit behaviour (although this was also a possibility), but believed that the mere perception of these actors and singers would immediately infect the spectator. Jacob stresses the importance of Matthew v.28 (‘But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart’) as one of the bases of this understanding of sense perception and morality. Side by side with his study of Chrysostom's condemnation of non-Christian spectacles, he describes the preacher's conception of the Church as a spiritual theatre, a benevolent alternative that possessed a similar potential to affect its viewers' moral state. The same power of the worldly theatre's aesthetic experience, which turned people into sinners, could be used to inspire virtue and improve people's souls. In the spiritual theatre, people would benefit from their tendency to imitate what they viewed. Jacob demonstrates how Chrysostom used the term ‘theatre’, especially in the sense of a public event, to describe the context of the preaching of Jesus and the Apostles, as well as Church services, festivals and visits to local ascetics. All of these public events would inspire people to imitate good examples. Even more broadly, Chrysostom spoke of life in general and even heaven as theatres of a sort. The final part of the book gives a sense of how Chrysostom's hopes for a transformation of public life, for the Christianisation of an entire way of life including the spectacles, were not widely shared. Unfortunately, recent publications related to these topics are missing from the bibliography due to the sad circumstances surrounding the book's delayed publication. The author died in 1996, the year after he completed this work as his Habilitation thesis. The preface explains that Jacob's wife and colleagues later completed the manuscript for publication.